Vegetation succession on cut slopes covered with exotic grasses for erosion control, Mt. Sakurajima

Abstract

The utilization of exotic grasses as cover plants for erosion control has received considerable attention in recent years, particularly because these exotic grasses have the potential to become invasive. This study examined succession of exotic grass communities that have been established on the cut slopes of the volcano, Mt. Sakurajima. The results showed that although the exotic grasses, such as Cynodon dactylon, Festuca rubra and Dactylis glomerata, that have been used for erosion control on the cut slopes were dominant for the first two years, marked decreases were observed as the native herbaceous plant, Miscanthus sinensis, became dominant after three years. By the sixth year, all of the exotic grasses vanished completely. This high rate of succession would result in the suppression of exotic grass dispersal on Mt. Sakurajima. It was also suggested that the chemical properties of volcanic soils, and the bio-engineering technique employed on Mt. Sakurajima may facilitate this high rate of succession.